Cancer nanotechnology is a rapidly growing research area in nanomedicine involving disease diagnostics and therapy1,2. During the past decade, engineered nanoparticles integrated with multimodality/multifunctionality have enabled imaging of cancer cells with high sensitivity and demonstrated successful delivery of pre-loaded therapeutic drugs in a targeted manner3-7. Multimodal nanoparticles that are integrated with optical and magnetic imaging modalities8,9 have demonstrated strong potential to facilitate pre-operative cancer diagnosis by MRI and optical based imaging10-13, to provide intra-operative surgical guidance (by optically demarcating tumor tissue from healthy tissue), and to track tumor metastasis2,7,8.
Current nanoparticle technology allows for imaging of particles carrying therapeutic drugs3,6,7,10,14,15. However, no activatable drug delivery system has been reported to date that has demonstrated the ability to directly confirm intracellular drug release upon reaction with a cytosolic biomolecule. Up until now, challenges in designing and constructing a nanoparticle integrating imaging, monitoring, and therapeutic functionalities in a single unit have restricted the fabrication of such a nanoparticle system.